Night-vision contact lenses may be in your future

Mar. 28, 2014 - 06:00AM
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Night-vision goggle technology has become more effective, streamlined and nimble in the past 10 years. But what if you could ditch that bulky headgear and pop in a pair of night-vision contact lenses?

It may sound like science fiction, but such dime-sized, lightweight optics may be possible in the future, thanks to researchers at the University of Michigan who have created a material that absorbs infrared rays at room temperature and translates them into an electrical signal, much like a silicon chip works with visible light inside a digital camera.

Night-vision contact lenses are still years away, but the engineers working on the base material, Ted Norris and Zhaohui Zhong of Michigan’s College of Engineering, are building a simple camera to prove their material has commercial application.

“If we integrate it with a contact lens or other wearable electronics, it expands your vision,” Zhong said. “It provides you another way of interacting with your environment.”

Here’s what you need to know:

1.What it is. Graphene is a single-atom layer of graphite. It’s the same material found in that No. 2 pencil you chewed on in school, but constructed so thinly that it’s actually considered two-dimensional. Graphene absorbs a large part of the electromagnetic spectrum, ranging from infrared — the wavelength picked up by NVGs that allows you to see in the dark — to ultraviolet.

2. How it works. Scientists have known since the mid-2000s that graphene absorbs infrared light. But at one atom thick, it can absorb only 2.3 percent of the light that hits it — and that’s insufficient to generate an electric signal strong enough for hardware to convert into a viewable image. “It’s a hundred to a thousand times lower than what a commercial device would require,” Zhong said.

Norris, Zhong and other researchers sandwiched an insulating layer between two graphene layers and then added electric current. When infrared light hits the layered product, its electrical reaction is amplified strongly enough to be converted into an infrared image.

3. What it could be used for (civilian): Norris and Zhong see possibilities that include chips in smartphone cameras for handy night vision, “smart” automobile windshields that improve night driving, improved thermal imaging in search and rescue robots, and new devices that allow doctors to monitor blood flow.

4. What it could be used for (military): This lightweight, super-strong material could eventually make its way into night-vision glasses or contact lenses and other imaging devices such as thermal imaging cameras, aircraft gimbal turrets, missile launch detectors and more.

5. What’s next? The researchers already have been able to produce infrared sensors the size of a pinky fingernail — also about the size of a standard contact lens.

“If we integrate it with a contact lens or other wearable electronics, it expands your vision,” Zhong said. “It provides you another way of interacting with your environment.”

Zhong and Norris are now working on their first camera but will need to pair up with commercial interests or rely on their own entrepreneurial efforts to move their material from the lab to contact lenses and other real-world applications.

“We’re materials scientists, not device people,” Norris said. “But what we do recognize is there are things we can do with these graphene layers that we couldn’t do with other traditional semi-conductors. It has opened up a lot of exciting possibilities,” Norris said.